The question of the century....

Is it possible to install a late model(thick center plate) 20b into a LHD FD3S chassis with a factory subframe, untouched firewall, and un-molested steering rack???
***as far back as possible to sit in-between the steering rack and firewall.***

Currently in progress of test fitting everything and it seems to be extremely tight as of right now. I am using an auto bellhousing with starter. I have to open up the tunnel underneath the shifter area due to the transmission's size, but as of right now the engine is still resting on the steering rack so that should clear up some space if I can drop the engine in its "slot".

 

As far as I know it hasn't been done. There just isn't enough room without moving something. There are basically 4 ways to do it.

Cutting the firewall is a good functional option labor/cost intensive. A custom firewall will have to be constructed. The shifter also ends up moving back slightly. It works well because you do not have to move the steering rack or alter the geometry.

Move the motor forward. This saves the time/money involved in cutting the firewall but the subframe needs to be modified to move the steering rack down and forward to clear the oil pan. The downside to this is the steering geometry becomes altered, and the car will have a tendency to bump steer because the front wheels will change toe as the suspension moves through its normal range of travel. A custom oil pan will need to be made or the stock one modified.

The third option is a compromise between the two. The motor is set back slightly but not so much that it interferes with the firewall. The subframe is modified slightly to reposition the rack and a bump steer correction kit is used to help get the geometery back to stock. A custom oil pan will need to be made or the stock one modified. This one seems to be the most common option.

The fourth and in my opinion best option is a short crank 3 rotor. Several companies offer machining of a 13b center plate to accept a stationary gear, which is thinner than the 20b plate. A shorter motor is easier to mount as you will have more room to the firewall and less interference with the steering rack. This can also be quite expensive.

The auto bell housing is large and bulky. You would have an easier time fitting a manual of aftermarket bellhousing. That of course means you need to use a manual rear plate on the motor and the correct adapter.

I've done conversions and worked on cars that were done just about every which way. I'm building a car for a customer right now going with option and a quicktime bellhousing mated to a T56. There is slight modification required to the trans tunnel.

 

Anymore info on this? What about the driveshaft, starter, wiring, etc...

 

A custom driveshaft needs to be made. We are using a cobra rear end so will be using a cobra driveshaft which will have to be shortened. This configuration is designed to work with the fd automatic starter. Wiring will all be custom.

 

The Defined kit I had in the shop had steel stock welded directly to the subframe and the motor hard mounted to that, so technically it isn't bolt in. Maybe yours is different Gordon?

 

I'm probably the only one who has done his own 20b swap with the engine moved back with a modified stock subframe. Mine sits back 5-1/2". From my own experience, you'll never get the engine to sit behind the rack unless you massage the firewall and remove and rebuild the rear half of the factory subframe. The rear half of the subframe won't let the engine lower enough. Once it's back that far, you will need to shorten the LIM or buy the Xcessive short version. Search for my thread in the 20b section from years back.

https://www.rx7club.com/20b-forum-95/20b-moved-back-pics-info-937928/

 

^ what 20b mount do you have?

what is the advantage of the scalloped rotors?

 

the DA 20b kit i had was all bolt on... and tvon is correct.. no way to get the pineapple to sit behind the rack..
the LIM on mine was shortened to clear the hood.. fuel rail sitting really tight against the manifolds...